Satellite-based navigation may be used to navigate an aircraft, e.g., during landing of the aircraft. In order to ensure the safety of the aircraft, it is important to monitor the integrity of the navigation locations. Present integrity monitoring measures the consistency of locations obtained from different combinations of satellite signals within a constellation to detect anomalous signals from individual satellites. However, this approach does not handle the case of an anomaly in the control segment of a global navigation satellite system which could affect some or all satellites in the system, or the case of intentional spoofing of satellite signals in the region of the navigation user equipment.